1. Field of the Invention
This invention relates to a display panel, and more particularly to a barrier rib composition capable of improving a strength of a barrier rib in the plasma display panel.
2. Description of the Related Art
Generally, a plasma display panel(PDP) radiates a fluorescent body by an ultraviolet with a wavelength of 147 nm generated during a discharge of He+Xe or Ne+Xe gas to thereby display a picture including characters and graphics. Such a PDP is easy to be made into a thin film and large-dimension type. Moreover, the PDP provides a very improved picture quality owing to a recent technical development. The PDP is largely classified into a direct current (DC) driving system and an alternating current (AC) driving system.
The PDP of AC driving system is expected to be highlighted into a future display device because it has advantages in the low voltage drive and a prolonged life in comparison to the PDP of DC driving system. Also, the PDP of alternating current driving system allows an alternating voltage signal to be applied between electrodes having dielectric layer therebetween to generate a discharge every half-period of the signal, thereby displaying a picture. Since such an AC driving system PDP uses a dielectric material, the surface of the dielectric material is charged with wall charge. The AC-type PDP allows a memory effect to be produced by a wall charge accumulated to the dielectric material due to the discharge.
FIG. 1 and FIG. 2 are a perspective view and a sectional view of a conventional AC-type PDP having a discharge cell arranged in a matrix pattern, respectively. In FIG. 2, the AC-type PDP is illustrated in a state of rotating a lower plate at 90xc2x0 for the sake of an easy understanding. The AC-type PDP includes a front substrate 10 provided with a sustaining electrode pair 12A and 12B, and a rear substrate 18 provided with an address electrode 20. The front substrate 10 and the rear substrate 18 are spaced in parallel with having a barrier rib 24 therebetween. A mixture gas such as Nexe2x88x92Xe or Hexe2x88x92Xe, etc. is injected into a discharge space defined by the front substrate 10 and the rear substrate 18 and the barrier rib 24. Any one of the sustaining electrode pair is used as a scanning/sustaining electrode 12A that responds to a scanning pulse applied in an address interval to cause an opposite discharge along with the address electrode 20 while responding to a sustaining pulse applied in a sustaining interval to cause a surface discharge with the adjacent sustaining electrode 12B. The sustaining electrode 12B adjacent to the scanning/sustaining electrode 12A is used as a common sustaining electrode to which a sustaining pulse is applied commonly. A distance a between the sustaining electrodes 12A and 12B making a pair is set to be approximately 100 xcexcm. On the front substrate 1 provided with the sustaining electrodes 12A and 12B, a dielectric layer 14 and a protective film 16 are disposed. The dielectric layer 14 is responsible for limiting a plasma discharge current as well as accumulating a wall charge during the discharge. The protective film 16 prevents a damage of the dielectric layer 14 caused by a sputtering generated during the plasma discharge and improves an emission efficiency of secondary electrons. This protective film 16 is usually made from MgO. Barrier ribs 24 for dividing the discharge space is extended perpendicularly at the rear substrate 18, and the address electrode 20 is formed between the barrier ribs 24. On the rear substrate 18 provided with the barrier ribs 24 and the address electrode 20, a fluorescent layer 26 excited by a vacuum ultraviolet Ray to generate a visible light is provided.
As shown in FIG. 3, such a discharge cell is arranged in a matrix pattern. At each of the discharge cells (11), scanning/sustaining electrode lines Y1 to Ym, common sustaining electrode lines Z1 to Zm and address electrode lines X1 to Xn are crossed with respect to each other. The scanning/sustaining electrode lines Y1 to Ym and the common sustaining electrode lines Z1 to Zm consist of the sustaining electrodes 12A and 12B making a pair. The address electrode lines X1 to Xn consist of the address electrode 20.
In the PDP having the above-mentioned configuration, the barrier ribs 24 support the front substrate 10 and the rear substrate 18. Also, the barrier ribs 24 prevent an ultraviolet ray generated by the discharge from being leaked into the adjacent discharge cell and reflect a rear light emitted from the fluorescent layer 26, thereby increasing the brightness of the PDP. The top portion of the barrier rib 24 has a black color so as to improve the contrast of a screen.
A process of fabricating the barrier ribs 24 will be described below. First, ceramic powder is usually mixed with an organic binder and an organic solvent, etc to be made into a paste state. Subsequently, the mixed paste is used to form a pattern on the rear substrate 18 by the screen printing technique and then is dried and tempered, thereby forming the barrier ribs. Otherwise, the barrier ribs 24 may be formed by entirely printing the paste on the rear substrate 18 and drying it and thereafter patterning the paste using the sand blast technique and tempering it.
However, the ceramic tempered material has a problem in that, since it is an inorganic material, a compressed strength is strong while a tensile strength is weak in accordance with an intrinsic characteristic of cermic. Accordingly, the conventional barrier ribs 24 made from the ceramic tempered material generate a crack by a tensile force induced by vertical compressive force exerting on the barrier ribs 24 during a process of attaching the front substrate 10 to the rear substrate 18. Also, the conventional barrier ribs 24 made from the ceramic tempered material may experience its partial damage due to an exterior impact during a fabrication process and a transportation of the product.
Accordingly, it is an object of the present invention to provide a composition of barrier rib material that is capable of improving a strength of a barrier rib in a plasma display panel.
In order to achieve these and other objects of the invention, a composition of barrier rib material for a plasma display panel according to one aspect of the present invention includes a barrier rib material paste; and a fiber material with a certain tensile strength.